Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV19)
DOI: https://doi.org/10.29363/nanoge.hopv.2020.161
Publication date: 6th February 2020
Concentration and Mobility of Ions in Methylammonium Lead Iodide Thin Films from Dielectric Response
M. Sajedi Alvar, G.A.H. Wetzelaer and P.W.M. Blom
Max Planck Institute for Polymer Research, Ackermannweg10, 55128 Mainz, Germany
For a quantitative modelling of devices based on methylammonium lead iodid (MAPbI3) understanding of its dielectric properties are indispensable. Ion migration plays an important role in the magnitude and frequency dependence of the dielectric constant of MAPbI3. From impedance spectroscopy measurements on Au/MAPbI3/Au capacitors we have extracted a diffusion coefficient for positive ions of 1×10-15 m2/s. This diffusion coefficient has been verified by measuring the dielectric displacement as a function of frequency. From the magnitude of the dielectric displacement an ion concentration of 2×1025 m-3 is obtained. Using drift - diffusion numerical simulations the effect of ion motion and voltage scan speed on the electric field distribution in MAPbI3 based devices can be predicted.